Reversible screw propeller



E. DUERR.

REVERSIBLE SCREW PROPELLER.

APPLICATION FILED NOV. 14, 192|.

Patent-ed Oct. 110, 1923,

Patented @et l0, MEZ.

EDGAR DUERR, 0F BELLA VISTA, ENGLAND.

REVERSIBLE SCREW PROPELLER.

Application led November 14, 1921. Serial No. 515,063.

T 0 all 'whom it may concern.'

Be it knownv that I, EDGAR DUERR, a subject of the King of Great Britainand Ireland, and resident of Bella Vlsta, Langham Road, Bowdon, in thecounty of Chester, England, have invented certaln new. and use fulImprovements in Reversible Screw Propellers, of which the following 1s aspeciication.

This invention relates to screw propellers of the type in which theangularity of the propellerblades with relatlon to the axls of thepropeller shaft can be altered to reverse the direction of propulsionofthe boat or the like to which the propeller is fitted.

The object of my invention is to provide an improved arrangement of themeans for operating the propeller blades which shall be strong,efficient and reliable, shall permit of the b-lades being turned to anydeslred position and shall automatically lock the blades in suchposition.

My invention comprises the combination witheach propeller blade of apinion thereon engaged at opposite points by two pinions keyed to ashaft by keys in right and leftl hand spiral keyways so that endwisemovement of the shaft imparts opposite angular movements to the pinionsthereon and so turns the propeller blades to any desired angle.

My invention further comprises the details of construction andarrangement hereinafter described and claimed.

,to is disposed a shaft Referring to the accompanying sheet ofexplanatory drawings Figure l is a sectional elevation and Figure 2 anend view of a reversible screw propeller constructed and arranged in oneconvenient form in accordance with my invention.

The same reference letters in the two views indicate the same parts.

In the illustrated application of my invention, the propeller boss ismade in three parts, one part a being secured upon a hollow drivingshaft b, a second part c which carries the blades d and their reversingmechanism and which screws on to the first part, and a third part ewhich is screwed into the second part. The complete boss may be of anydesired external form.

Within the hollow shaft b before referred f having right and left handspiral keywa s g therein, the said central shaft passing tiirough thepropeller is given longitudinal movement, the two pinions L, z' thereonare turned through equal angles in opposite directions and so turn thepropeller blades d. The latter can be turned to any position from afeathering position to one giving full ahead or full astern motion tothe boat to which the propeller is fitted. By reasonbf the arrangementof the two pinions upon the shaft f,

vthe propeller blades are self locking in any position and no saidshaft.

The drive to the propeller may be arranged through both the hollow andcentral shafts -or through either of these. In the arrangementillustrated, the part 7c is attached to the engine driving shaft or itsequivalent and the end of the shaft b is keyed therein. The rod f1passes through a cross head or disc m which is attached to a slidingcollar .n by rods o. The latter pass through holes inpart m and arethereby caused to rotate the cross head m and the rod f1. A suitablefork or its equivalent operated by hand or by power traverses the collarn-and the shaft f for altering the angular position of the propellerblades.

To give strength to the propeller blades, these are each supported atboth sides of the pinion thereon as shown. To place the blades inposition they are threaded into the boss through the bevel pinions, thelatter being pinned to prevent unscrewing.

The propeller is simple to assemble, readily manipulated for reversingand speed controlling purposes, and the blades are not liable to readyfracture or breakage from the boss or to become jammed duringoperations. It can be used upon aircraft, as a fan or exhauster and forother purposes.

f desired, instead of traversing the shaft b from the engine side of thepropeller it may be operated from the opposite side and the propellershaft b be made solid.

l. In reversible screw propellers, the comtorque is transmitted to theybinatibn with a plurality of blades, a boss meme@ el a shaft in seidbose, e

peil o Wheels om,

seid shaft epgegng said pnons, right and left hund Spual key and keyweyconnections between seid shaft and said Wheels, and

:means for imparting longitudinal movements to seid shaft relativ es Setforth.

ely to sold Wheels,

ln testimony whereof l have signed Edy name to this specoetlon.

GAR DUREE.

